The real-time analysis technologies such as video analysis and audio analysis can detect abnormal events in the field. Generally, operators manually analyze data from sensors located near an event to become aware of a situation or to learn details of an event. The operators manually select related information from periodic or continuous sensor data to become more aware of the situation or to learn more details of the event. This procedure leads to delay in the operators' reaction to abnormal events because the analysis results and the sensor data used for the analysis may be insufficient to make a decision for responding to the event.